Displacement occurs when one party unfairly or inappropriately replaces another. If you arrive at work to find someone else sitting at your desk, you might want to complain to your boss about your recent displacement.
Displacement can be a depressing topic, given that it often involves people being forced to leave somewhere where they belong. However, for a more cheerful take on this word, put your foot in the bathtub and watch the water level rise. Scientifically speaking, your foot is causing displacement of the water. It was this observation that led Archimedes to develop his famous principle about buoyancy (and, perhaps more famously, to run through the streets naked in celebration).